The present invention relates to a material for forming, for example, semiconductor wiring films, to a film forming method, and to films.
Recently, the progress in the semiconductor field is remarkable. For example, LSIs are being shifted toward ULSIs. Miniaturization is being developed to improve the signal processing speed. Copper having a low resistance is selected as wiring conductor materials and the spacing between wiring conductors is filled with a material having a very low dielectric constant. There is a demand for thinning films of those materials. Moreover, it has been studied that the gate oxide film is formed of a metal oxide film such as HfO2.
Even if the above-mentioned technical idea is adopted, the micro-patterning leads to extremely shallow diffusion layers at the source-drain regions, and thus increases the resistance components thereof. Therefore, it is difficult to improve the signal processing speed.
Not only the contact at the source-drain region but also the resistance of the gate electrode have been perceived as problems. For that reason, it has been long wanted to develop new materials.
In order to overcome such problems, metal silicides such as TiSi2 or CoSi2 have been studied (refer to Japanese Patent Laid-open Publication No. H6-204173).
However, it is predicted that TiSi2 or CoSi2 has a limit to gain the performance in future.
In view of such a limitation, the present inventor et al. consider that NiSi must be introduced for the future semiconductor elements.
It was considered that the NiSi thin film can be easily produced using the sputtering technique.
However, the sputtering physically damages the semiconductor elements. Moreover, NiSi may react with Si, being a base substrate, at high temperatures to make NiSi2. This results in poor film uniformity.
Accordingly, it was found that it is not preferable to form a NiSi film through sputtering.